Accuracy and reliability of virtual femur measurement from CT scan

Ismail, Napsiah; Abdullah, Nurliza; Noor, Noor Maizura Mohamad; Lai, Poh Soon; Shafie, Mohamed Swarhib; Nor, Faridah Mohd

doi:10.1016/j.jflm.2019.02.010

Cited by 15 publications

(5 citation statements)

References 27 publications

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“…In this research, the aim was solely to evaluate if the observation medium (macroscopic observation, 3D surface scans, CT scans) made a difference in how the observer perceived the sutures. This approach is in line with other studies that have attempted to quantify potential differences induced by observation media, although these tend to focus on measurement-based methodologies rather than those relying on descriptive criteria [31,32], despite the fact that these descriptive In the CT model (C), the edges of the sutures appear closer together, "rounded", and less complex than in the dry bone observation. This image demonstrates the shift in perception between three observation media.…”

Section: Discussionsupporting

confidence: 63%

Virtual anthropology: a preliminary test of macroscopic observation versus 3D surface scans and computed tomography (CT) scans

Abegg

Balbo

Domínguez

et al. 2020

Forensic Sciences Research

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Virtual anthropology (VA) is based on applying anthropological methods currently used to analyse bones to 3D models of human remains. While great advances have been made in this endeavour in the past decade, several interrogations concerning how reliable these models are and what their proper use should be remain unanswered. In this research, a fundamental assumption of VA has been investigated: if the way we perceive and apply an anthropological method is truly similar when looking at bones macroscopically and through various 3D media. In order to answer, 10 skulls of known age and sex were scanned using a computed tomography (CT) scanner and a 3D surface scanner. Two observers separately applied a defined staging method to eight suture sites on these skulls, first looking at the bone macroscopically, then at the 3D surface scan, and finally on the CT scan. Two rounds of observation were carried out by each observer. Intra-and inter-observer error were evaluated, and two sample t-tests used to evaluate if the different types of medium used yielded significantly different observations. The results show a high degree of inter-observer error, and that data obtained from 3D surface scans differ from macroscopic observation (confidence level 95%, P 0.05). CT scans, in these settings, yielded results comparable to those obtained through macroscopic observations. These results offer many possibilities for future research, including indications on the kind of anthropological methods and anatomical landmarks that might be reliably transferable to the virtual environment. All current methods used in traditional anthropology should be tested, and if they prove unreliable, new techniques to analyse bones from virtual models should be developed. KEY POINTSLarge discrepancies between observation on dry bones and computer-generated 3D models (surface scans or CT scans) could lead to the re-evaluation of the suitability of traditional anthropological methods for application on 3D models. This preliminary study evaluates whether macroscopic, 3D surface scans, and CT scans viewings generate different observations. The results indicate that the data are not always coherent across all three media of observation. Explanations include the aspect given to the bone by the 3D software, differences between handling bones in real life versus on a computer, and level of expertise of the observers.

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Section: Discussionsupporting

confidence: 63%

Virtual anthropology: a preliminary test of macroscopic observation versus 3D surface scans and computed tomography (CT) scans

Abegg

Balbo

Domínguez

et al. 2020

Forensic Sciences Research

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“…3,5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Studies have proven that though osteometric measurements using dry bones were considered the gold standard by most anthropologists, the use of imaging especially PMCT is equally acceptable when compared to measurements obtained from dry bones with the advantage of being faster and reproducible. 28 Though most studies have shown that the lower extremity has the greatest association with body stature, there are often missing or badly fragmented body parts found at the scene of death. For this reason, in this present study, we used the spine as it could be often found intact as a whole or as part of the body trunk.…”

Section: Discussionmentioning

confidence: 99%

“…Studies have proven that though osteometric measurements using dry bones were considered the gold standard by most anthropologists, the use of imaging especially PMCT is equally acceptable when compared to measurements obtained from dry bones with the advantage of being faster and reproducible. 28…”

Section: Discussionmentioning

confidence: 99%

Stature estimation of Malaysians using post-mortem computed tomography images of the spine

Singh

Lai

Sidek

et al. 2022

Proceedings of Singapore Healthcare

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Background Stature estimation is important in medical investigations to identify victims and is most accurate using anatomical methods utilizing the entire skeleton. However, in cases of mass fatalities, it has been calculated using regression analysis formulas of different body parts. Radiology especially post-mortem computed tomography (PMCT) is increasingly being used in victim identification as it is non- invasive and allows for multi planar reconstruction. Methods This study aims to generate stature estimation formulae using regression analysis of the vertebral column incorporating population that form the Malaysian ancestry i.e. Malay, Chinese and Indian using PMCT. This was a retrospective study involving 115 subjects who had a PMCT. Subjects consisted of Malaysian males and females (92 males and 23 females) aged 18–70 years. Cervical length (CL), thoracic length (TL), lumbar length and the whole spine length (WSL) incorporating cervical, thoracic and lumbar length were compared against cadaveric length. Results Whole spine length had the highest correlation coefficient of 0.570 and showed highest correlation with cadaveric length among female subjects compared to males. Whole spine length amongst the Malay was the highest followed by the Chinese and Indian ethnic groups (r = 0.671, 0.629, 0.402). Conclusion Our study concluded that the use of WSL from PMCT images can be used for body height estimation amongst Malaysians. This study has also successfully generated population-specific database for Malaysian experts to perform stature estimation using measurements of the vertebral column.

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“…However, Cappella et al [17] uses a 7.5% threshold for both intra‐ and interobserver error for atlanto‐occipital measurements. In a study of virtual femoral measurements, Ismail et al [18] indicates that measurements with coefficients of reliability <0.9 and rTEMs >5% should be treated with caution. They report that coefficients of reliability >0.95 are indicative of negligible errors.…”

Section: Discussionmentioning

confidence: 99%

“…However, Cappella et al [17] uses a 7.5% threshold for both intra-and interobserver error for atlanto-occipital measurements. In a study of virtual femoral measurements, Ismail et al [18] indicates that measurements with coefficients of reliability <0.9…”

Section: Intra-observer and Interobserver Errormentioning

confidence: 99%

Investigating error in saw mark minimum kerf width measurements

VanBaarle

Garvin

2022

Journal of Forensic Sciences

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Minimum kerf width (MKW) is often assessed in medicolegal cases of skeletal sharp force trauma and can provide information about the tool used. Previously published saw MKW research focuses on the relationship between MKW and saw blade set width (width of the saw blade including tooth set). Despite these publications using various measurement tools and methods to collect MKW, error in MKW measurements is not well‐documented. The goal of this research was to investigate MKW measurement precision in terms of intraobserver error, interobserver error, and the effects of measurement modality (e.g., calipers versus stereo microscope). The study sample consisted of 351 incomplete cuts made with 27 diverse saws. MKW was collected using three methods: (1) inserting the internal caliper jaws into the incomplete kerf, (2) placing the external caliper jaws on the cortical surface, and (3) using a digital stereo microscope and associated measurement software. For each method, intraobserver error and interobserver error were assessed. Differences in measurements taken with the three measurement modalities were assessed for each observer as well. Relative technical error of measurement (rTEM) and coefficients of reliability indicate that internal caliper and stereo microscope measurements had the lowest intra‐ and interobserver error (rTEM = 3.72% to 6.15%; r = 0.98–0.996). External caliper measurements performed the worst (rTEM: intra = 8.53% and inter = 21.32%). There was higher precision between internal caliper and stereo microscope measurements than with the external caliper measurements. This research highlights the need for measurement standardization.

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Accuracy and reliability of virtual femur measurement from CT scan

Cited by 15 publications

References 27 publications

Virtual anthropology: a preliminary test of macroscopic observation versus 3D surface scans and computed tomography (CT) scans

Virtual anthropology: a preliminary test of macroscopic observation versus 3D surface scans and computed tomography (CT) scans

Stature estimation of Malaysians using post-mortem computed tomography images of the spine

Investigating error in saw mark minimum kerf width measurements

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